Technical Field
The present invention relates to a diagnostic endoscopic imaging support apparatus and method, and a non-transitory computer readable medium on which is recorded a diagnostic endoscopic imaging support program, capable of identifying an actual tip position of an endoscope in a three-dimensional image of a subject obtained in advance.
Background Art
Recently, the technology of observing and treating tubular tissues of patients, such as large intestines, small intestines, bronchi, and the like, has been drawing attention.
While endoscopic imaging may provide vivid images of the colors and textures in the tubular tissues represented by image sensors, such as a CCD (Charge Coupled Device) and the like, it represents interiors of the tubular tissues as a two-dimensional image, so that it is difficult to understand which position of the tubular tissue the image indicates.
Consequently, technology in which a route to a target point within a tubular tissue is obtained in advance using three-dimensional image data obtained in advance through tomographic imaging by a modality, such as CT (Computed Tomography) or the like, then a virtual endoscopic image which is similar to an endoscopic image actually obtained by an endoscope is generated using the aforementioned three-dimensional image data, and the route to the target point is navigated using the virtual endoscopic image is proposed (refer to Japanese Unexamined Patent Publication No. 2006-198031 and Japanese Unexamined Patent Publication No. 2000-135215).
When displaying a virtual endoscopic image like that described above, it is necessary to identify the position in the three-dimensional image data corresponding to the tip position of the endoscope actually inserted into the tubular tissue. Consequently, for example, T. Yamaguchi et al., “Oblique-viewing Endoscopic Navigation System with Simultaneous Display of Virtual and Real Endoscopic Images”, Technical Report of IEICE, MI, Medical Image, Vol. 103, Issue 213, pp. 43-46, 2003 proposes the use of an optical sensor or a magnetic sensor in order to identify the actual tip position of the endoscope in a tubular tissue.
Further, in order to identify the position of an endoscope as in T. Yamaguchi et al., “Oblique-viewing Endoscopic Navigation System with Simultaneous Display of Virtual and Real Endoscopic Images”, Technical Report of IEICE, MI, Medical Image, Vol. 103, Issue 213, pp. 43-46, 2003, many methods are proposed in which the endoscope is provided with a marker which can be detected by a sensor and the camera position is identified by detecting the marker.
Further, Japanese Unexamined Patent Publication No. 2006-149972, Japanese Unexamined Patent Publication No. 2007-007180, and Japanese Unexamined Patent Publication No. 2003-245242, Japanese Unexamined Patent Publication No. 2004-000551, and Japanese Unexamined Patent Publication No. 2002-369790 propose methods for sensing what shapes the flexible endoscopes inserted into the bodies have.
Conventionally, the tip position of an endoscope is tracked, for example, by a magnetic sensor and, by considering the relative position between the pre-operation image and in-operation image, the position in the pre-operation image which is deemed to be the same as the tip position of the endoscope during operation is identified, and the virtual endoscopic image of the identified position is displayed.